In data transmission systems such as digital communications systems, net-worked computer systems and the like, efforts are being made increasingly to design the terminal devices so that they can be connected to the system by plugging them into connector boxes. The interruption of the data transmission cable represented by plug connection to a connector box means a considerable increase in the characteristic impedance, so that, especially at high transmission rates and thus in the presence of high frequencies, large attenuation losses occur.
Before a data transmission cable can be connected to the jack of the connector box, the shielding around the cable must be removed. As a result, the data line can pick up interference and at high transfer frequencies, it actually functions as an antenna which sends out unwanted signals.